Multi-break air-or gas-blast circuit breakers



Oct 1956 c. H. FLURSCHElM ET AL 2,765,354

MULTI-BREAK AIR-OR GAS-BLAST CIRCUIT BREAKERS Flled March 2, 1954 6 Sheets-Sheet l I gr ggoas WM W mk-Tv mk ATTORNEYS 1956 c. H. FLURSCHEIM ET AL 2,766,354

MULTI-BREAK AIR-OR GAS-BLAST CIRCUIT BREAKERS Flled March 2, 1954 6 Sheets-Sheet 2 f I7 :7 H6 H6 I0 I! I0 I I RL R R WIN Ill lllllllil ATTORNEYS Och 1956 c. H. FLURSCHEIM ET AL 2,766,354

MULTI-BREAK AIR-OR GAS-BLAST CIRCUIT BREAKERS Flled March 2, 1954 6 Sheets-Sheet 3 INV ENTORS DOW 1,,

ATTORNEYS Get. 9, 1956 C. H. FLURSCHEIM ET AL MULTI-BREIAK AIR-OR GAS-BLAST CIRCUIT BREAKERS Flled March 2, 1954 FIG.4.

6 Sheets-Sheet 4 w WIINi/ENTOR? ATTORNEYS Flled March 2, 1954 1955 c. H. FLURSCHEIM ET AL 2,756,354

MULTI-BREAK AIR-OR GAS-BLAST CIRCUIT BREAKERS 6 Sheets-Sheet 5 law NToRs hm; hm

ATTORNEYS R R R2 {2%, Q, 1956 c. H. FLURSCHEIM ET AL 2,766,354

MULTI-BREAK AIR-OR GAS-BLAST CIRCUIT BREAKERS FlledMaIch 2, 1954 s Sheets-Sheet e IHHIIII III! FIG. 9.

i IIHIIIIIIHI'II ATTORNEYS United States Patent MULTI-BREAK AJR- OR GAS-BLAST CIRCUIT BREAKERS Cedric Harold Flurscheim, Hale,

Manchester, and John Barker, signors to Metropolitan-Vickers Electrical Company Limited, London, England, a British company Cecil Arthur Fawdrey, Abram, England, as-

This invention relates to multi-break airor gas-blast circuit breakers and particularly to such breakers of the kind in which a plurality of interrupter units, adapted for connection in series and each comprising a housing containing nozzles and moving contacts arranged to provide circuit interruption with blast-assisted arc extinction, are supported upon a common insulating column arranged for conveying the blast air or gas to the interrupter units.

It is an object of the invention to provide a circuit breaker of the above kind having a novel arrangement of interrupter units on the common support column, which arrangement, being more compact than hitherto, permits an increased number of breaks to be provided without increasing to any great extent the overall dimensions of the circuit breaker.

According to the present invention an airor gasblast circuit breaker of the kind specified comprises a set of series-connected interrupter units supported in pairs on a common insulating column by means of at least two insulating tubes (hereinafter referred to as insulating branch tubes) branching from the top of the column and each carrying a pair of the interrupter units of the set, the arrangement of branch tubes and interrupter units being generally symmetrical with respect to an axial plane of the column and such that the air or gas paths from the support column to the interrupter units through the branch tubes are substantially equal in length.

The insulating branch tubes carry respective pairs of interrupter units extending outwardly of and on opposite sides of a plane including the axes of the appertaining branch tube and of the support column, the interrupter units preferably being horizontally aligned in each pair. Conveniently each such pair of interrupter units is mounted on a metallic member carried at the outer end of the appertaining branch tube, this member being arranged to permit passage of air or gas from the branch tube equally into the two interrupters and also constituting an electrical connection between the inner ends of the two interrupter units.

The insulating branch tubes may themselves be mounted on a metallic member surmounting the main support column and suitably formed to permit the passage of air or gas from the support column equally into the branch tubes.

In one basic arrangement of circuit breaker in accordance with the invention two pairs of interrupter units arearranged in the manner indicated above on metal members carried at the end of respective insulating branch tubes, as of porcelain, which extend outwardly in opposite directions, preferably with an upward inclination, from diametrically opposite positions 011 a metallic mounting member at the top of the common support column. This last mentioned mounting member may be electrically connected to a point electrically midway between the mounting members carried by the two insulating branch tubes, whereby these branch tubes will be subjected in operation to substantially equal voltages. Furthermore this basic arrangement, which assuming one ice break per interrupter unit will provide four breaks for the circuit breaker, may be augmented to provide two further breaks by providing an additional pair of interrupter units also mounted on a further branch tube which may be insulating but as will appear hereinafter will advantageously be conductive. In either case the number of breaks can be doubled by providing two sets of interrupter units similarly mounted on respective support columns and arranged for interconnection through an isolating switch.

The invention, together with further objects, features and advantages thereof will be more fully apparent from the following description of the accompanying drawings which illustrate by way of example various air-blast circuit breaker arrangements each including two sets of interrupter units mounted on respective insulating columns in accordance with the invention and arranged for interconnection by a rotatable isolating bar.

In particular,

Figs. 1, 2 and 3 are a plan view, side view and elevation respectively of a circuit breaker having two sets of interrupter units each arranged in accordance with the so-called basic arrangement of the invention referred to above,

Figs. 4, 5 and 6 are similar views of a circuit breaker having two sets of interrupter units each arranged in accordance with the first of the so-called augmented arrangements mentioned above, and

Figs. 7, 8 and 9 are again similar views of a circuit breaker having two sets of interrupter units each arranged in accordance with the second of the so-called augmented arrangements mentioned above.

Dealing first with the composition and disposition of each set of interrupter units in the various arrangements, in Figs. 1, 2 and 3 each set comprises two pairs of interrupter units 11 and 2-2 supported on a common insulating column 3 by means of respective insulating branch tubes 4 which extend outwardly and upwardly in generally opposite directions from a metallic mounting member 5 surmounting the column 3. The interrupter units of each pair extend in horizontal alignment outwardly of the appertaining branch tube 4 from a metallic mounting member 6 carried at the outer end of the branch tube, the mounting member 6 also serving to interconnect the interrupters of the pair at their inner ends so that they are electrically in series. The mounting member 5 at the top of the column and the mounting members 6 at the outer ends of the branch tubes are so formed as to permit a blast of air passed up the column 3 to pass equally to the four interrupter units whereby in well-known manner to operate them or at least to assist in arc extinction. The required series-connection of the interrupter units of each set is eifected by means of a conductor 8 which is connected between an outer end of the interrupter pair 1-1 and the remote outer end of the interrupter pair 2-2, this being most clearly seen in Fig. 1. Owing to the symmetry of the arrangement, the mid-point of the conductor 8 substantially coincides with the axis of the support column 3 and in order that in operation the two insulating branch tubes 4 will be subjected to substantially equal voltages the conductor 8 is connected at its midpoint, as by a conducting rod or pin 9 (Fig. 2), to the metallic mounting member 6 surmounting the column 3 with the result that the insulating tubes 4 will each be subjected to the voltage appearing across one interrupter unit. If it were considered that equality of voltage across the branch tubes 4 was not absolutely necessary, the connection 9 could be omitted in which event the insulating tubes 4 could form part of the major insulation to earth.

In the arrangement shown in Figs. 4, 5 and 6 each set of interrupter units again comprises two pairs of hori- J zontally aligned interrupters 1'1' and 2'-2' supported on a common insulating column 3' by means of respective insulating branch tubes 4 which extend outwardly and upwardly from a metallic mounting member 5 surmounting the column 3 and carry the interrupter pairs at their'outer ends on respective metallic mounting members 6. In this arrangement however two additional horizontally aligned interrupter units -10 are carried by a common metallic interconnecting member 11 mounted on a further branch tube 12' which extends upwardly and outwardly from the mounting member 5' on the column. The three pairs of interrupter units 11", 22 and 1ii19 are disposed substantially in the same horizontal plane and are so arranged as to define three sides of a rectangular figure as is clearly illustrated in Fig; 4. (The open sides of the rectangular figures defined by the interrupter pairs in the two sets face towards each other to facilitate engagement of the isolating bar as will be' described later.) The required serieg-connection of the interrupter pairs is effected-by means of connectors 13 directly connecting the interrupter units adjacent each of the two corners defined between the interrupter pairs. The additional branch tube 12 may be of insulating material, but preferably it is metallic so as to constitute an electrical connection between the mounting member 5 surmounting the column 3' and the mounting member lit by which the additional interrupter units 101tl are carried and interconnected. In this way the insulating branch tubes 4 will in operation be subjected to substantially equal voltages, namely equal to the voltage appearing across two interrupter units.

in the arrangement of Figs. 7, 8 and 9 each set of interrupter units again includes two pairs of horizontally aligned interrupter units 1l" and 22' supported on a common insulating column 3 by means of respective insulating branch tubes 4" which extend outwardly and upwardly from a metallic mounting member 5" surmounting the column 3 and carry the interrupter pairs at their outer ends on respective mounting members 6". in this arrangement two additional horizontally alignediuterrupter units 1tl'llii are carried by a common metallic interconnecting member 11' mounted on a further branch tube 12 which extends coaxially upwardly from the main support column 3". The interrupter units of the additional pair 1ti'1l extend outwardly from the member 11 in a vertical plane which lies between and substantially parallel to the vertical plane containing the other interrupter pairs 1"1 and 2"2" respectively. The required series-connection of the interrupter pairs is effected by means of connectors 13 directly connecting one of the interrupter units ltlwith the nearer of the interrupter units 1 and the other of the interrupter units it)" with the nearer of the interrupter units 2" as illustrated most clearly in Fig. 7. In this arrangement again, as in that of Figs. 4, 5 and 6, the additional branch tube 12 may be insulating, but is preferably metallic so as to constitute an electrical connection between the members 5" and 11' whereby in operation the insulating branch tubes 4 will be subjected to equal voltages, namely equal to the voltage across two interrupter units.

Turning now to the interconnection of the two sets of interrupter units in each of the arrangements illustrated in the drawings, this is eriected in each case by means of a transverse conductive bar or the like 14 mounted on an insulating support pillar 15- for rotation thereon or therewith about the pillar axis whereby to be rotatable into and out of a position at which it eficcts connection between the series circuits through the respective sets of interrupter units. To this end the interrupter units of each set are so arranged and interconnected that a terminal T at the outer end of one of the end interrupter units of the series circuit through the set faces generally in the direction towards. the support pillar 15 for the isolating bar 14 so as to be engageable by an end of the isolating bar 14, the terminals T of the two sets being arranged to lie at diametrically opposite positions with respect to the axis of the support pillar 15. The remaining terminal L of the series circuit through each interrupter set thus becomes a supply terminal for the overall series circuit established through the two sets by the isolating bar 14-.

Supply conductors will normally be arranged to extend from these supply terminals L in a direction away from the support pillar 15 for the isolating bar 14. This can readily be done in the arrangement of Figs. 1, 2 and 3 and that of Figs. 7, Sand 9 since the disposition andintcrconnection of the interrupter units of a set in these arrangements is such that with the terminal T facing generally towards the support pillar 15 for engagement by the isolating bar 14', the terminal L is necessarily disposed at a position remote from the support column 15 and is thus in a convenient position for connection with a supply conductor. In the case of the arrangement shown in Figs. 4, 5 and 6 however, the positioning of the terminal T to face generally towards the pillar 15 for engagement by the isolating bar 1'4 results in the terminal L of the set also having a position towards the pillar 15. In such case the associated supply conductor may require to be carried over the set of interrupter units and for this purpose there is shown for each set of interrupter units in the arrangement of Figs. 4, 5 and 6 an upwardly extending insulator 16 which is mounted on the pair'of interrupter units providing the terminal L at a position adjacent the outer end of that pair remote from'the terminal L, which insulator 16 supports a conductor 17 passing over the set of interrupter units in the direction away from the pillar 15 as shown.

It is contemplated that the support columns for the sets of interrupter unitsand the support pillar for the isolating bar will be mounted on a common base 7 (for instance on the top of an elongated tank constituting a reservoir for air or gas for the associated interrupters) with their axis arranged (as shown) in a common vertical planeconstituting the plane of symmetry for the sets of interrupter units.

in carrying out the invention the interrupter units may, in accordance with well-known practice, be shunted by linear or non-linear resistances R.

What we claims is:

l. A multi-break airor gas-blast circuit breaker, comprising an insulating support column serving also for blast conveyance, at least two insulating branch tubes diverging from adjacent thestop of the column, and a pair of interrupter units mounted adjacent the outer end of each branch tube in position extending outwardly of and on opposite sides of the plane containing the axes of the appertaining branch tube and the support column respectively, which interrupter units comprise respective housings each containing nozzles and moving contacts arranged to provide circuit interruption with blast-assisted arc extinction, the interrupter units from the several pairs being connected in series, andthe arrangement of branch tubes and interrupter units being generally symmetrical with respect to an axial plane of the column and such that the blast paths to the respective interrupter units through the support column and branch tubes are substantially equal in length.

2. A multi-b'reak circuit breaker as claimed in claim 1. including metallic mounting members carried respectively by the branch tubes at their outer ends and each having mounted thereon the pair of interrupter units for the appertaining branch tube, said mounting members permitting blast to pass equally'into the associated interrupter units from the branch tube and constituting an electric connection between these units at theirinner ends.

3. A multi-b reak circuit breaker as claimed'in claim 2 including two such branch tubes having respective mounting members each carrying such a pair of interrupter units, which circuit breaker includes also a further metallic mounting member surmounting the column and carrying said two branch tubes in position diverging with respect to each other, this further mounting member permitting blast to pass from the column equally into the branch tubes and being electrically connected to a point electrically midway between the mounting members on the respective branch tubes, whereby to subject the branch tubes to substantially equal voltage stressing in operation.

4. A multi-break circuit breaker as claimed in claim 3 in which the axes of said two branch tubes and of the column are substantially co-planar and the two pairs of interrupter units extend substantially parallel to each other, which circuit breaker includes for connecting the two pairs of interrupter units in series a conductor which extends between an outer end of one pair and the remote outer end of the other pair and is connected adjacent its mid point to the mounting member surmounting the column, said conductor having in operation a potential midway between that of the mounting members on the respective branch tubes.

5. A multi-break circuit breaker as claimed in claim 3 including a further branch tube mounted on said mounting member that surmounts the column, said further branch tube being divergent with respect to the other two branch tubes, a further metallic mounting member carried by said further branch tube, and an additional pair of interrupter units mounted on this last mentioned mounting member in position extending outwardly of and on opposite sides or" a plane including the axes of said further branch tube and the column, which additional pair of interrupter units is connected in series between the other two pairs, the last mentioned mounting member permitting blast to pass equaily from the further branch tube into the associated interrupter units and constituting an electrical connection between these units at their inner ends.

6. A mul-ti-break circuit breaker as claimed in claim 5 in which said further branch tube is metallic and constitutes an electrical connection between said further mounting member carried thereby (which member will in operation have a potential midway between the potentials of the mounting members carried by the other branch tubes) and said mounting member surmounting the column.

7. A circuit breaker as claimed in claim 5 in which the three pairs of interrupter units are so disposed on the appertaining branch tubes as to define respectively three sides of a generally quadrilateral figure, interconnection of the pairs of interrupter units being effected by interconnecting adjacent outer ends of the pairs at the two corners defined by said three sides of the quadrilateral figure.

8. A circuit breaker as claimed in claim 5 in which said further branch tube extends upwardly from the support column substantially co-axi'ally therewith and carries the additional pair of interrupter units at its upper end.

9. A circuit breaker as claimed in claim 8 in which the additional interrupter units extend from the upwardly extending branch tube substantially in a common vertical plane lying between and generally parallel to respective vertical planes containing the other pairs of interrupter units, the interconnection of the pairs of interrupter units being effected by connecting an outer end of the additional pair with the adjacent outer end of one of the other pairs and the other outer end of the additional pair with the adjacent outer end of the remaining pair.

10. A multi-break airor gas-blast circuit breaker comprising two insulating support columns serving also for blast conveyance, at least two insulating branch tubes diverging from adjacent the top of each said column, a pair of interrupter units mounted adjacent the outer end of each branch tube in position extending outwardly of and on opposite sides of the plane containing the axes of the apertaining branch tube and support column respectively, which interrupter units comprise respective housings each containing nozzles and moving contacts arranged to provide circuit interruption with blast-assisted arc extinction, the set of interrupter units from the several pairs associated with each column being con nected in series and the arrangement of branch tubes and interrupter units on each column being generally symmetrical with respect to an axial plane of the column and such that the blast paths to the respective interrupter units through the column and branch tubes are substantially equal in length, and an isolating switch through which the two sets of series-connected interrupter units can be interconnected.

11. A multi-break circuit breaker as claimed in claim 10 including a support pillar positioned between said two support columns, and a transversely extending conductive bar mounted on this pillar for rotation about the axis thereof into and out of a position at which it effects connection between a terminal of the series circuit through the set of interrupter units on one support column and a terminal of the series circuit through the set of interrupter units on the other support column, whereby said transverse bar constitutes an isolating switch between said sets.

12. A multi-break circuit breaker as claimed in claim 11 in which in each said set of interrupter units the outer end of the interrupter unit at one end of the series circuit through the set is disposed towards said support pillar, and carries a terminal engageable by an end of the isolating bar, the arrangement being such that the terminals thus provide for the two sets are disposed at diametrically opposite positions with respect to the axis of said pillar.

References Cited in the file of this patent UNITED STATES PATENTS 1,904,577 Uebermuth Apr. 28, 1933 1,920,894 Ruppel Aug. 1, 1933 2,658,128 Forwald Nov. 3, 1953 2,677,739 Forwald May 4, 1954 FOREIGN PATENTS 541,949 Great Britain Dec. 18, 1941 

